Elastic gripping optoelectronic sensor for an energy consumption meter

ABSTRACT

The optoelectronic sensor is intended to be placed in a domestic energy consumption meter which comprises a rotary member (2) whose rotational speed is a function of energy consumption. The sensor (1) is accommodated in a support (7) comprising a tongue (18) allowing it to be fastened by elastic gripping to an existing part (15) inside the meter, the tongue maintaining the sensor (1) at a fixed distance from the rotary member (2) of the motor. The invention is used especially in electricity consumption meters.

FIELD OF THE INVENTION

The present invention relates to an optoelectronic sensor for domesticenergy consumption meters, such as electricity meters and gas meters.

BACKGROUND OF THE INVENTION

At the present time, electricity and gas meters display on their frontface a series of figures which express the consumption of electricity orgas. These figures are read periodically in order to prepare theconsumption invoice. These periodic readings create serious constraintsand involve a high outlay.

Many solutions have been provided for doing away with theabove-mentioned readings. These solutions have involved placing insidethe meter a sensor capable of detecting the passage of a reference markon a rotary disc during each revolution of the latter.

Whenever the reference mark is detected, an electronic componentassociated with the sensor supplies an electrical signal. Theseelectrical signals can be converted into electricity or gas consumption.

The reading of the consumption can thus be carried out remotely.

However, fastening these sensors inside the electricity and gas meterspresents difficulties.

In fact, it is important to place these sensors at a constant and exactdistance from the rotary disc carrying the reference mark, so as toobtain reliable and reproducible measurements.

The solutions provided hitherto are unsatisfactory because they entailmodifications to the meters and excessive assembly times.

The object of the present invention is to overcome the disadvantages ofthe above-mentioned solutions.

SUMMARY OF THE INVENTION

The invention is therefore aimed at an optoelectronic sensor for adomestic energy consumption meter which comprises a rotary member ofwhich the rotational speed is a function of the consumption, this sensorbeing intended to be placed inside the meter in order to detect thepassage of a reference mark of the rotary member during each revolutionof the latter.

According to the invention, the sensor is accommodated in a supportcomprising means allowing it to be fastened to an existing part insidethe meter, the means maintaining the sensor at a fixed distance from therotary member of the meter.

Thus, the mounting of the sensor is very easy and can be carried out ina very short time, since it requires no modification of the meter. Themeans for fastening the support can consist of a gripper capable ofgripping the existing part of the meter elastically.

The support in which the sensor is accommodated makes it easier tomanipulate the latter, while at the same time protecting it.

Moreover, this support, together with its quick-fastening means,guarantees a high mounting accuracy inside the meter.

According to an advantageous version of the invention, the conductorscoming from the sensor are embedded in a flexible tape made of aninsulating material sufficiently thin to be capable of passing betweenthe cover of the meter and the body of the latter, without anymodification of these.

According to a preferred version of the invention, the optoelectronicsensor can be fastened in an electricity consumption meter comprising,on the front face of its cover, an identification plate having anaperture, behind which a disc carrying a reference mark is mountedrotatably.

In this case, the support of the sensor preferably comprises a faceequipped with an elastic tongue capable of covering the edge of theidentification plate, this same face of the support having a catch whichcan be lodged at that end of the aperture of the identification plateadjacent to the edge of the latter covered by the tongue of the support.

Because the catch is engaged in the aperture of the identificationplate, the support of the sensor is wedged in the two longitudinaldirections of the aperture, on the one hand by the catch up against theend of this aperture and on the other hand by the bottom of the groovedefined by the tongue which is up against the edge of the plate.

Furthermore, the catch wedges the support in the two directions of widthof the aperture. Thus, the fastening of the support in relation to theaperture of the identification plate makes it possible accurately todefine the distance between the sensor and the rotary disc carrying thereference mark.

The sensor according to the invention can also be fastened in a gasmeter, the body of which comprises a series of graduated wheels drivenin rotation, one of these carrying a reference mark.

In this case, the support of the sensor preferably comprises a faceequipped with an elastic tongue capable of covering the edge of a wallextending inside the body, another face of the support having a shoulderintended for bearing against a surface of the body of the meter, inorder to maintain the sensor carried by the support at a particularconstant distance from the wheel carrying a reference mark.

Other particular features and advantages of the invention will alsoemerge from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings given by way of non-limiting examples:

FIG. 1 is an elevation view of one face of a first version of a sensorsupport for an electrical consumption meter,

FIG. 2 is a view of the opposite face of the support,

FIG. 3 is a diagrammatic perspective view of an electrical meter ofwhich the cover has been removed,

FIG. 4 is a front elevation view showing the support of the sensor inposition on the edge of the identification plate and opposite the rotarydisc,

FIG. 5 is a cut-away perspective view showing the fastening of thesupport to the identification plate,

FIG. 6 is a perspective view of the meter equipped with its cover,

FIG. 7 is an elevation view of a sensor support intended to be fastenedin a gas consumption meter,

FIG. 8 is a partial plan view of a gas meter which is without its coverand in which the sensor support is fastened.

DETAILED DESCRIPTION OF THE INVENTION

The embodiment of FIGS. 1 and 2 show an optoelectronic sensor 1 intendedto be fastened in an electricity consumption meter which comprises (seeFIGS. 3 to 5) a rotary disc 2 of which the rotational speed is afunction of the consumption, the sensor 1 being intended to detect thepassage of a reference mark 3 of the rotary disc 2 during eachrevolution of the latter.

The actual sensor 1 comprises, side by side, a diode emitting infraredradiation 4, for example consisting of gallium arsenide, and aphototransistor 5, for example consisting of silicon of the n-p-n type,this diode 4 and this phototransistor 5 being mounted in a plastic body6.

The diode 4 emits a radiation which is reflected on a reflecting surfacetowards to the phototransistor 5 which converts radiation received intoan electrical signal. So that the radiation emitted by the diode 4 canbe reflected towards to the phototransistor 5 with accuracy, thereflecting surface must be located at an exact distance from the sensor1.

Where an electricity consumption meter is concerned, the reflectingsurface consists of the rotary disc 2 which rotates at a speedproportional to the electrical power consumption.

This disc 2 from the outset carries a black reference mark 3 which isthus detected by the sensor 1 during each revolution.

According to the invention, the sensor 1 is accommodated in a support 7made, for example, of plastic and comprising means allowing it to befastened by elastic gripping to an existing part inside the meter, saidmeans maintaining the sensor 1 at a fixed distance d (see FIG. 4) fromthe rotary disc 2 of the meter.

FIGS. 2, 4, 5 and 6 show that the conductors 8, 9, 10 and 11 coming fromthe sensor 1 are embedded in a flexible tape 12 made of insulatingplastic sufficiently thin to be capable of passing (see FIG. 6) betweenthe cover 13 of the meter and the body 14 of the latter, without anymodification of these.

The electricity consumption meter comprises, on the front face of itscover 13, an identification plate 15 having a rectangular aperture 16,behind which (see FIGS. 3 and 5) the disc 2 carrying the black referencemark 3 is rotatably mounted.

The support 7 of the sensor 1 comprises a face 17 equipped with anelastic tongue 18 which extends parallel to this face 17 and which iscapable of covering the edge 15a of the identification plate 15, asindicated in FIG. 5. This same face 17 of the support 7 has a catch 19which can be lodged at that end 16a of the aperture 16 of theidentification plate 15 adjacent to the edge 15a of the latter coveredby the tongue 18 of the support 7.

The dimensions of the catch 19 correspond to that of the end 16a of theaperture 16, so that it can fit into the latter substantially withoutplay.

FIG. 5 also shows that the bottom 20a of the groove 20 defined betweenthe tongue 18 and the face 17 of the support 7 is located at a distancefrom the catch 19 substantially equal to the distance between the edge15a of the plate and the end 16a of the aperture of the latter. Thus,the catch 19 is wedged against the edge 16a of the aperture, and thebottom 20a of the groove 20 is wedged against the edge 15a of the plate.

Moreover, as illustrated in FIGS. 1, 4 and 5, the support 7 has a face21 perpendicular to that having the tongue 18 and the catch 19. Thisface 21 possesses an orifice 22 communicating with the receptacle of thesensor 1. The distance between the catch 19 and the face 21 isdetermined so as to maintain the sensor 1 accommodated behind theorifice 22 at a suitable constant distance d from the disc 2 rotatablymounted in a plane parallel to the face 21. This exactly determineddistance d allows the radiation emitted by the diode 4 to be reflectedon the disc 2 and be received by the phototransistor 5 after reflection.

Furthermore, the support 7 has a face 23 which is opposite the said face21 having the orifice 22 and from which emerge the conductors 8, 9, 10and 11 connected to the sensor 1.

The mounting of the support 7 in the electricity consumption meter isextremely simple.

It is sufficient to remove the cover 13 and engage the groove 20 definedby the tongue 18 onto the edge 15a of the plate opposite the aperture 16and then to push the support 7 towards this aperture until the catch 19engages in the end of the aperture.

The tape 12 having the conductors 8, 9, 10 and 11 connected to thesensor 1 is subsequently passed over the edge of the body 14 of themeter, and the cover 13 is then secured.

FIG. 7 illustrates a support 25 of the sensor 26 intended to be placedin a gas consumption meter. The body 27 of this meter (see FIG. 8)comprises a series of graduated wheels 28 driven in rotation. Therotational speed of these wheels 28 is proportional to the consumption.The last wheel 28 carries a reference mark 29 consisting, for example,of a black adhesive tape and intended to be detected by the sensor 26.

The support 25 of the sensor 26 comprises a face 30 equipped with anelastic tongue 31 capable of covering and gripping the edge 32a of awall 32 extending inside the body 27. Another face of the support 25 hasa shoulder 33 intended to bear against a surface 34 of the body 27 ofthe meter (see FIG. 7), in order to maintain the sensor 26 carried bythe support 25 at a particular constant distance d₁ from the wheel 28carrying a reference mark 29.

In the example illustrated in FIG. 8, the body 27 of the metercomprises, opposite the wheel 28 carrying a reference mark 29, areceptacle of a cross-section substantially in the form of a U opentowards the wheel and delimited by three walls 32, 35 and 36 of thebody. It can be seen from this FIG. 8 that the support 25 of the sensorhas a cross-section matched to the dimensions of the receptacle, so asto be capable of fitting into the latter.

As in the embodiment according to FIGS. 1 to 6, the mounting of thesupport 25 in the body 27 of the gas meter is very easy and requires nomodification of the meter. Likewise, the tape 37 carrying the conductorsconnected to the sensor 26 can be passed between the edge 38 of the body27 of the meter and the cover (not shown) of the latter.

Of course, the invention is not limited to the exemplary embodimentsjust described, and many modifications can be made to these, withoutdeparting from the scope of the invention.

I claim:
 1. Optoelectronic sensor for a domestic electricity consumption meter comprising a body (14), a cover (13), a rotary member (2) whose rotational speed is a function of the consumption, and an identification plate (15) located on said cover (13), said identification plate having an aperture (16) behind which the rotary member is rotatably mounted, said sensor (1) adapted to be placed inside the meter in order to detect the passage of a reference mark (3) of the rotary member during each revolution of the latter, said sensor (1) being accommodated in a support (7) comprising means (18) allowing said support to be fastened to an existing part (15) inside the meter, said means maintaining the sensor (1) at a fixed distance from the rotary member (2), said support (7) comprising a first face (17) equipped with an elastic tongue (18) capable of covering and elastically gripping an edge (15a) of the identification plate (15), said first face (17) having a catch (19) which can be lodged at an end of said aperture (16) adjacent to said edge (15a) of the identification plate covered by said tongue (18).
 2. Sensor according to claim 1, wherein conductors (8, 9, 10, 11) emanating from the sensor (1) are embedded in a flexible tape (12) made of an insulating material sufficiently thin so as to be capable of passing between the cover (13) and the body (14) of the meter, without any modification of these.
 3. Sensor according to claim 1, wherein the catch (19) has dimensions which correspond to those of said end of the aperture (16), so that said catch can fit into said aperture substantially without play.
 4. Sensor according to claim 1, wherein a groove (20) defined between the tongue (18) and said first face (17) of the support (7) has its bottom (20a) located at a distance from the catch (19) substantially equal to the distance between the edge (15a) of the identification plate and the end of the aperture (16).
 5. Sensor according to claim 2, wherein the support (7) has a second face (21) perpendicular to the first face (17) equipped with the tongue (18) and the catch (19), said second face (21) possessing an orifice (22) communicating with the sensor (1), the distance between the catch (19) and said second face (21) being determined so as to maintain the sensor (1) accommodated behind the orifice (22) at a suitable constant distance from the rotary member (2) rotatably mounted in a plane parallel to said second face (21).
 6. Sensor according to claim 5, wherein the support (7) has a third face (23), which is opposite said second face (21), and from which emerge said conductors (8, 9, 10, 11) connected to the sensor (1). 